Home design and retrofitting. techniques for wildfire defense

Transcription

1 Home design and retrofitting Landscaping and home design for wildfire defense techniques for wildfire defense Yana Valachovic Steve Quarles UC Cooperative Extension May 4, 2018

2 Today s presentation How homes burn from wildfire Near home vegetation and landscaping Vulnerabilities in home design Resources Thank Dr. Steve Quarles, UC fire durability expert (emeritus) now with the Insurance Institute for Business and Home Safety (IBHS), and UC Master Gardener volunteers for many of these slides and ideas.

3 Homes were the most combustible part of the landscape

4 How a house burns from wildfire? Ember / Firebrand Flame Contact Radiant Heat Tennessee Division of Forestry

5 Embers We Know That Wind blown embers are responsible for the majority of building ignitions Angora Fire South Lake Tahoe USDA FS, R5 TP 015

6 Fountain Grove, Santa Rosa 2017

7 Know the basics of fire: Fuel + Oxygen + Heat = Fire Fuel + Weather + Topography= Fire Behavior What can you control? Fuel is anything that will burn Dry or dead vegetation Wood siding, roofing, fencing Trees Woody shrubs or perennials Landscape mulch

8 Work from the house out Defensible Space Zone 1: 0-5 feet noncombustible zone Zone 2: 5-30 feet lean and green zone Zone 3: feet or to the property line reduced fuel zone

9 0 5 ft noncombustible zone to reduce chance of flame contact exposure Insurance Institute for Business & Home Safety Effective defensible space must be present on all sides of the home Insurance Institute for Business & Home Safety

10 Fire resistant plant lists? All plants can burn regardless of how they are marketed Fire safe landscaping requires maintenance (pruning, irrigation, clean up) Select low growing, open structured, less resinous, higher moisture content plants Native and drought tolerant can be options, if maintained well Tubbs Fire, Rich Casale, NRCS

11 University of California Cooperative Extension Bark mulch Mulch helps plants retain moisture, but it will burn too! Use hardscape, rock mulch or lawns <5 feet from the home. University of California Cooperative Extension Pine needle mulch Tubbs Fire University of California Cooperative Extension

12 Simulated embers exposure on a house

13 Roof (Priority #1)

14 Roof Edge Insurance Institute for Business & Home Safety University of California Cooperative Extension

15 Litter accumulation creates exposure to the wall unit (not protected with roofing). Insurance Institute for Business & Home Safety Insurance Institute for Business & Home Safety

16 Plastic gutter vs metal gutter Insurance Institute for Business & Home Safety Embers can ignite litter in rain gutters

17 Roof - Skylights University of California Cooperative Extension University of California Cooperative Extension

18 Vents (Priority #2) Through-roof (outlet) Gable end Under-eave (inlet) Foundation & other

19 Vents Ember Entry

20 Vents Mesh Size Use 1/8 inch or smaller 6 mm 3 mm

21 Vents California s Chapter 7A A Stephen Quarles C Stephen Quarles D Insurance Institute for Business & Home Safety B Stephen Quarles A=foundation vent with intumescent treatment (Vulcan), B=through roof vent with steel wool, C= gable vent with baffles, D= gable vent with intumescent (Embers Out)

22 Ridge vents Vulnerable to debris accumulation Insurance Institute for Business & Home Safety

23 Exterior Walls Vertical non-combustible zone Insurance Institute for Business & Home Safety Insurance Institute for Business & Home Safety Insurance Institute for Business & Home Safety University of California Cooperative Extension

24 Firewood under a deck Broom University of California Cooperative Extension

25 Deck: Attachment Detail Insurance Institute for Business & Home Safety Insurance Institute for Business & Home Safety Maintenance is critical and consider: Non combustible boards adjacent to the siding Foil faced tape on deck joists, ¼ gap between deck boards, 24 on center

26 University of California Cooperative Extension Stored building materials under a deck is vulnerable Insurance Institute for Business & Home Safety

27 Fence Vulnerability Stephen Quarles Stephen Quarles

28 Fence: Guidance University of California Cooperative Extension A metal gate can help prevent spread to home via a fence ignition.

29 A neighbor s house could be in the 5 30 ft zonetheir condition can affect your survival Insurance Institute for Business & Home Safety

30 Recommendations Good practices: remove stored fuels, debris, clean gutters 1. Roof: install and maintain a Class A rated roof covering. Install a metal drip edge and address other edge of roof vulnerabilities 2. Vents: upgrade to flame resistant and ember resistant 3. Non combustible zone should include the area 5 near the house, under the entire foot print of the deck, and 6 inches vertically upward from the ground to the start of your siding Redwood or cedar deck: For ember resistance use a foil faced bitumen tape applied to the top on deck joists, ¼ inch gap between deck boards, and 24 inch on center joist spacing CA Building Code Chapter 7A WUI construction: Home design, maintenance, and construction can be more important than any individual fire resistant building product when addressing ember ignition. Poor installation and maintenance can increase the vulnerability of a given product to an ember exposure.

31 For more information visit: June 13 th webinar see source/lessonslearned2017wildfires

32 From: Home Survival in Wildfire Prone Areas